Display devices, such as laptop computers, tablet computers, slate computers, smart phones, and the like, may use a modulating display panel, such as a liquid crystal display, in combination with a backlight to display images to users. Various backlights are known for such display devices. Some backlight sources, such as light-emitting diodes, are used in combination with a diffuser to distribute light with an acceptably uniform intensity, while others, such as electroluminescent panels, may provide a suitably uniform intensity without a diffuser. Such backlights generally output light having a broad intensity distribution. As a result, a relatively large luminous flux may be output at potentially high angles relative to a normal of the display panel surface plane.